1. Field of the Invention:
The present invention relates to an automatic center adjusting roller bearing.
2. Description of the Art:
It has been known that, during operation of an automatic center adjusting roller bearing, when rollers do not roll normally, for example, when the rollers roll with a large skew angle, an inconvenience such as an increase of friction and heat generation in the inside of the bearing is caused which results in a reduction of the rolling fatigue life of the bearing.
For this reason, various techniques for controlling the skew angle of the bearing during operation have been developed. For example, raceway surfaces of an inner race and an outer race respectively are made to have different shapes of generating lines and to have different radii of curvature. Alternately, relative surface roughness between the raceway surface of the inner race or outer race and the rolling surface of the roller are made different from each other.
However, the measure to use the inner race and the outer race having raceway surfaces of different generating line shapes and different radii of curvature requires the combination of the inner race and the outer race having very complicated shapes of generating lines and radii of curvature. Further, in the measure to use the inner race, the outer race, and the rollers in which the relative surface roughness between the raceway surfaces of the inner race and the outer race and the rolling surfaces of the rollers are different, it is necessary to take the relationship with a counterpart component into consideration. As a result, it is practically difficult to effectively manufacture a bearing to control the skew. Furthermore, since various factors such as the shape of the generating lines of the raceway surfaces of the inner and outer races, the surface roughness of these raceways and the roller rolling surface, and the like, affect the skew of the rollers in combination, there factors must be determined from the point of overall consideration. Accordingly, freedom in the design of the bearing is restricted to a great extent.